Dapsone first came into medicine as an antibacterial agent but was found to be less effective than other sulfonamides. Likewise its activity against tuberculosis was disappointing. Nevertheless, it has been the main stay in the treatment of leprosy. It also has some action against malaria and other parasites. Nowadays, after leprosy, dapsone has proved as a valuable drug in the treatment of a wide range of mainly uncommon and rare dermatoses. In this article, we present a comprehensive review of the mechanisms of action, pharmacokinetics, uses, adverse reactions and management of side effects of dapsone.